title: Immediate and follow-up results for 44 consecutive cases of small (<10 mm) internal carotid artery aneurysms treated with the pipeline embolization device.
abstract: BACKGROUND
  The pipeline embolization device (PED) provides effective, durable and safe endovascular reconstruction of large and giant intracranial aneurysms. However, 80% of all cerebral aneurysms found in the general population are less than 10 mm in size. Treatment of small aneurysms (<10 mm) with flow diverters may be advantageous over endosaccular modalities that carry risks of procedural rupture during aneurysm access or coil placement.
  
  
  METHODS
  We retrospectively reviewed a prospective, single-center aneurysm database to identify all patients with small (<10 mm) internal carotid artery (ICA) aneurysms who underwent endovascular treatment using the PED. Patient demographics, aneurysm characteristics, procedural details, complications, and technical and clinical outcomes were analyzed.
  
  
  RESULTS
  Forty-four cases were performed in 41 patients (age range 31-78 years). PED was successfully implanted in 42 cases. A single PED was used in 37/42 (88%) cases. Mean postprocedure hospital stay was 1.7 ± 0.3 days and 98% of patients were discharged home. Major complication occurred in one patient (2.3%), who died of early subarachnoid hemorrhage. Transient neurological deficit, delayed intracerebral hemorrhage (asymptomatic), and delayed groin infection occurred in one patient each. Follow-up rate was 91.8% (45 aneurysms in 35 patients) with a mean follow-up of 4.0 ± 1.9 months. By 6 months post-PED implantation, angiographic success (complete or near complete aneurysm occlusion) was observed in 80%. Mild (<50%), asymptomatic, nonflow limiting in-stent stenosis was observed in 5.4% (2/37 cases). All the 35 patients with follow-up remained at preprocedure neurological baseline.
  
  
  CONCLUSIONS
  Small (<10 mm) ICA aneurysm treatment with PED implantation is safe and carries a high rate of early angiographic success.
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, The Johns Hopkins Hospital, 1800 Orleans Street, Baltimore, MD 21287, USA.
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Lin
authors.forename: Geoffrey P
authors.initials: GP
authors.lastname: Colby
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Kim
authors.forename: Judy
authors.initials: J
authors.lastname: Huang
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Tamargo
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Coon
keywords: Cerebral aneurysms; flow diverter; pipeline embolization device